Tem Proxy

The main task of these two popular technologies is to provide security for the Internet user. Despite a certain similarity of tasks, they are performed absolutely differently. Proxy, although it allows you to remain anonymous and bypass blocked sites, it is still quite vulnerable, especially when it comes to untested services. VPN in this regard looks preferable, because thanks to end-to-end encryption it reliably protects information from the entry point to the exit point.

In CentOS, if there is no graphical interface (from the terminal), proxy configuration is done through the export http_proxy=http://User:Pass@Proxy:Port/ command. Accordingly, User is the user, Pass is the password to identify you, Proxy is the IP address of the proxy, and Port is the port number. If you have DE, the configuration can be done via Network Manager (as in any other Linux distribution).

Transferring a large byte array using UDP involves breaking the data into smaller chunks and sending each chunk as a separate UDP datagram. Since UDP is a connectionless protocol, there's no guarantee that the chunks will arrive in the same order they were sent. Therefore, you'll also need to send additional information to reassemble the data correctly at the receiver side.

Here's a simple example using Python to send and receive large byte arrays using UDP:

1. Sender (Python script send_large_data.py):

import socket

def send_large_data(data, host, port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    chunk_size = 1024

    total_chunks = len(data) // chunk_size + 1
    sequence_number = 0

    for i in range(total_chunks):
        start = sequence_number * chunk_size
        end = start + chunk_size
        chunk = data[start:end]

        sock.sendto(chunk, (host, port))
        sequence_number += 1

    sock.close()

if __name__ == "__main__":
    large_data = b"This is a large byte array sent using UDP." * 100
    host = "127.0.0.1"
    port = 12345
    send_large_data(large_data, host, port)

2. Receiver (Python script receive_large_data.py):

import socket

def receive_large_data(host, port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    chunk_size = 1024
    total_chunks = 0
    received_data = b""

    while True:
        data, address = sock.recvfrom(chunk_size)
        total_chunks += 1
        received_data += data

        if len(received_data) >= (total_chunks - 1) * chunk_size:
            break

    sock.close()
    return received_data

if __name__ == "__main__":
    host = "127.0.0.1"
    port = 12345
    large_data = receive_large_data(host, port)
    print("Received data:", large_data)

In this example, the sender script send_large_data.py breaks the large byte array into chunks of 1024 bytes and sends each chunk as a separate UDP datagram. The receiver script receive_large_data.py receives the chunks and reassembles them into the original byte array.

To read a video stream received via UDP, you can follow these steps:

1. Choose a programming language: Python, C++, Java, or any other language that supports UDP communication.

2. Set up a UDP server: Create a UDP server that listens for incoming video stream data. This server will receive the video stream packets and store them in memory or on disk.

3. Parse the UDP packets: The video stream data will be sent in a series of UDP packets. You will need to parse these packets to extract the video frames and reassemble them into a complete video stream.

4. Decode the video frames: Once you have the video frames, you need to decode them to convert them from their compressed format (e.g., H.264, MPEG-4) to a raw video format that can be displayed.

5. Display or save the video stream: After decoding the video frames, you can either display them in real-time or save them to a file for later playback.

Here's an example of how you might implement this in Python using the socket and cv2 libraries:

import socket
import cv2
import struct

# Create a UDP server socket
server_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
server_socket.bind(('0.0.0.0', 12345))

# Variables to store the video stream
frame_length = 0
frame_data = b''

# Loop to receive video stream packets
while True:
    data, address = server_socket.recvfrom(1024)
    frame_length += struct.unpack('I', data[:4])[0]
    frame_data += data[4:]

    # Check if we have enough data for a complete frame
    if frame_length > 0 and len(frame_data) >= frame_length:
        # Extract the video frame
        frame = cv2.imdecode(np.frombuffer(frame_data[:frame_length], dtype=np.uint8), cv2.IMREAD_COLOR)
        # Display or save the video frame
        cv2.imshow('Video Stream', frame)
        cv2.waitKey(1)

        # Reset variables for the next frame
        frame_length = 0
        frame_data = b''

Note that this is a simplified example and assumes that the video stream is using a specific protocol for packetization and framing. In practice, you will need to adapt this code to the specific format of the video stream you are receiving. Additionally, you may need to handle network errors, packet loss, and other issues that can arise during UDP communication.

Google Chrome doesn't have a built-in function to work with a proxy server, although there is such an item in the settings. But when you click on it, you are automatically "redirected" to the standard proxy settings in Windows (or any other operating system).